Field of the Invention
The present invention relates to an oscillation circuit, and more particularly to a crystal oscillation circuit, a gain stage of the crystal oscillation circuit and a method for designing the same.
Description of Related Art
Crystal oscillation circuits are important components in a variety of circuits in electronic devices for generating an oscillation frequency required by the circuits. Currently, one of the most common crystal oscillation circuits is, for example, Pierce oscillator, which serves as a gain stage in the form of an inverter, and the circuit thereof is simple, efficient and stable. In general, the gain stage of conventional crystal oscillation circuits has a fixed gain parameter. When selecting different gain stages of the crystal oscillation circuits, a system designer needs to take the power consumption of the whole circuit into consideration sufficiently. However, the difference between the gains of different gain stages in conventional crystal oscillation circuits is too large to be suitable for optimization of the parameters of the crystal oscillation circuits. It is an issue to be overcome how to develop a gain stage that enables a user to set an optimization parameter flexibly according to the environment.